BUFFALO, N.Y. — Obese drivers are far less likely to wear seatbelts than are drivers of normal weight, a new University at Buffalo study has found, a behavior that puts them at greater risk of severe injury or death during motor vehicle crashes.

The UB study found that normal weight drivers are 67 percent more likely to wear a seatbelt than morbidly obese drivers. Drivers were considered overweight or obese if they had a BMI (body mass index) of 25 or more, according to the World Health Organization definition of obesity, with 25-30 defined as overweight, 30-35 slightly obese, 35-40 moderately obese and 40 morbidly obese.